This invention relates to an apparatus and method for alleviating or preventing excessive pressure, and therefore pressure sores, from developing on a contacted body area.
A pressure sore is any lesion caused by excessive, unrelieved pressure on an area of the body. When pressures above normal homeostatic pressure are applied to a body region and its associated blood vessels, the blood vessels can partially or fully collapse, thereby disrupting normal circulation. As a result, the affected area becomes devoid of blood supply, which prohibits oxygen and nutrients from being delivered to the surrounding tissue. Pressure sores often occur over bony prominences, and can range in severity from partial thickness skin loss to full thickness skin loss with tissue necrosis and damage to underlying muscle and bone.
Pressure sores are a common and costly problem in bed and chair-bound individuals, as well as in patients having an impaired ability to reposition themselves, such as those on ventilators or under anesthesia. In such individuals, various areas of the body may be permanently or almost permanently in contact with the support surface of the bed or chair, resulting in excessive pressure, lack of air circulation, and often increased shear between the contacted body area and the support surface.
Various systems have been proposed to reduce or prevent pressure sores. Among the most common prevention systems are mattresses, cushions, or pads that include some type of raised members extending from a flat base as shown, for example, in U.S. Pat. No. 5,153,956 issued to Nold. The raised members are spaced apart and designed to contact the body at numerous points in an attempt to lower the pressure between the affected body area and the support surface and equalize the pressure over the entire surface of the body. In order to be effective in this capacity, the raised members are designed to be of a height sufficient to maintain the body away from the base. However, upon the application of pressure by contact with the body, the raised members tend to bend and collapse into contact with the base, such that the body is resting against a substantially flat surface with broad points of contact. This action negates any lowering of pressure of the affected area, while also decreasing aeration and increasing the potential for shear between the body member and the pad.
Another problem for bed or chair bound persons is maintaining a comfortable temperature for body surfaces that are in contact with a supporting surface. In particular, when ambient temperatures are hot, persons confined to a bed or wheelchair may sweat profusely on a supporting surface. If ambient temperatures are cool persons with poor circulation may be uncomfortable if they must lie or sit on an unheated supporting surface for an extended period of time.
Persons riding in vehicles for extended periods of time may also suffer from unrelieved pressure that may compress or restrict blood vessels in localized areas. Vehicle seats may also be uncomfortable at high or low temperatures if the seat has no temperature control system. It is known to provide resistance heating elements in vehicle seats to warm the seats in cold weather. However, cooling seats during warm weather has proven to be a difficult problem. No single system for heating and cooling vehicle seats is known that permits efficient and effective heating and cooling that may be controlled and operated in conjunction with the vehicle heating and air conditioning system.
These and other problems and drawbacks attendant to the prior art are addressed by this application as will be apparent to one of ordinary skill in the art to which the invention relates in view of the following description and attached drawings as summarized below.
Therefore, it is an object according to the present invention to provide an apparatus and method for pressure management, including alleviating or preventing excessive pressure development on a contacted body area.
It is a further object according to the present invention to provide an apparatus and method for alleviating or preventing excessive pressure development on a body area that function reliably regardless of the pressure applied by the contacted body area.
It is a still further object according to the present invention to provide an apparatus and method for alleviating or preventing excessive pressure development on a body area wherein the apparatus is embodied in a cushion or the like.
Still another object according to the present invention is to provide an apparatus for alleviating pressure which incorporates a member having a first end for exerting focused pressure upon the body area.
Yet another object according to the present invention is to provide a breathable cover for an apparatus for alleviating excessive pressure wherein the breathable cover shields the apparatus from unwanted foreign agents and is easy to clean and store.
A further object according to the present invention is to combine a hospital appliance such as a chair or bed with differently sized covered apparatus usable across various areas of the appliance to accommodate different portions of a user""s body.
An additional object according to the present invention is to provide a supporting surface for a person that alleviates excessive pressure and provides for heating or cooling of the surface.
According to yet another object of the invention, a vehicle seat is provided that has a seating surface on the seat back or seat base that alleviates excessive pressure. The vehicle seat may also provides for heating or cooling of the surface.
Accordingly, a cushion apparatus for alleviating, and preferably preventing, excessive pressure development on a body area is provided. The cushion includes a first, bottom surface and a second, top surface which is spaced from the first surface, and where the first surface has a plurality of holes formed therethrough. A compressible inner layer is disposed between the first and second surfaces, and a plurality of elongate members are supported by the inner layer and disposed at least partially within the holes. The members have distal ends that extend at least partially through the holes to project beyond the first surface, and in the absence of pressure the members are located at a neutral position. In operation, pressure applied to the distal ends by contact with the body area cause the members to be displaced axially along the holes away from the neutral position and toward the bottom surface without deformation. A cover encloses the cushion and includes an upper layer that engages the distal ends of the members.
The cushion apparatus may include a heating and cooling system that directs either warm or cool air between the first surface of the cushion and upper layer of the cover.
The cushion apparatus may also be placed upon or incorporated into a vehicle seat. Either the seat back or seat base could have the cushion. The vehicle seat could also incorporate air ducts for directing HVAC air through the cushion.
In a preferred embodiment, the members are longer than the distance between the top and bottom surfaces, such that the members extend beyond the top surface independent of the applied pressure in order to maintain a plurality of point pressures on a body area. In addition, the members include second ends located beneath the top surface, where each second end preferably includes an enlarged base operable to limit the distance that each member projects beyond the top surface. These second ends can be attached to the inner layer, which is preferably operable to return the members to the neutral position upon removal of the applied pressure.
In further accordance with a preferred embodiment of the present invention, the members have rounded first ends for added comfort when in contact with the body area. At least a subset of the channels are preferably densely spaced in order to provide a plurality of point pressures to the contacted body area. In terms of materials, the top and bottom surfaces are preferably constructed from a material, such as plastic, that is rigid relative to the inner layer. Additionally, the inner layer is preferably constructed of a foam material and the members can be constructed from either a rigid plastic or metallic material. In a preferred embodiment, the apparatus includes fasteners affixed thereto that are operable to removably attach the apparatus to another object, such as a standard chair, wheelchair, mattress, or to a part of the human body such as the heel or elbow.
Correspondingly, a method for alleviating or preventing excessive pressure development on a body area is provided. The method includes providing an apparatus which has a bottom surface, a top surface which is spaced from the bottom surface and has a plurality of channels formed therethrough, and a compressible inner layer which is disposed between the top and bottom surfaces. The method also includes providing a plurality of elongate, inflexible members which are supported by the inner layer and disposed at least partially within the channels, the members having first ends that extend at least partially through the channels to project beyond the top surface, such that in the absence of pressure the members are located at a neutral position. The method further includes applying pressure to one or more of the first ends by contact with the body area, thereby creating a plurality of point pressures on the body area. Still further, the method includes displacing the members axially along the channels away from the neutral position and toward the bottom surface without deformation so as to maintain the plurality of point pressures and prevent excessive pressure from developing on the body area.
In a preferred embodiment, the method further includes returning the members substantially to the neutral position by removing contact of the body area with the one or more first ends. Furthermore, displacing the members axially is preferably limited by compression of the inner layer and the bottom surface. Still further, the method preferably includes removably attaching the apparatus to another object, such as a chair, wheelchair, or mattress, or to a part of the body such as the heel or elbow.
In another embodiment, disclosed is an apparatus for alleviating the excessive pressure development on a body area comprising a cushion including a bottom surface, a top surface spaced from the bottom surface, where a plurality of channels are formed through the top surface. Also included is a compressible inner layer which is disposed between the top and bottom surfaces, and a plurality of elongate, inflexible members supported by the inner layer and disposed at least partially within the channels. The members have first ends that extend at least partially through the channels to project beyond the top surface. The members are located at a neutral position in the absence of pressure. Pressure applied to the first ends by contact with the body area causes the members to be displaced axially along the channels away from the neutral position and toward the bottom surface without deformation. The apparatus also includes a cover for enclosing the cushion, the cover having a topper surface for engaging the first ends of the members, a base surface, a plurality of side surfaces, wherein the topper surface serves to limit the upward movement of the members. The topper surface of the cover may be a polymeric material and weft knitted fabric, and the base surface of the cover may be formed of hard vinyl material.
At least some of the plurality of members may have longitudinally extending shaft portions and first ends supported by the shaft portions, wherein the first ends have a tapered head configuration to focus the applied pressure upon the body area. Further, the top and bottom surfaces may be attached by fasteners disposed therebetween. Also, the topper surface of the cover may include a thin, impermeable membrane to provide moisture protection to the cushion, or such membrane may be separately and generally disposed between member first ends and topper surface.
Another apparatus according to the present invention includes a plurality of channels formed through a top surface, a compressible inner layer disposed below and proximate to the top surface, and a plurality of elongate, inflexible members supported by the inner layer and disposed at least partially within the channels. The members have first ends that extend at least partially through the channels to project beyond the top surface. In the absence of pressure, the members are located at a neutral position, wherein pressure applied to the first ends by contact with the body area causes the members to be displaced axially along the channels away from the neutral position without deformation. At least some of the plurality of members have first ends with a relatively large, tapered head configuration to focus the applied pressure upon the body area. The apparatus may also include a cover having a topper surface, a base surface, and a plurality of side surfaces for enclosing the top surface, the inner layer and the inflexible members. At least some of the members have shaft portions which are elongated for supporting the first ends. The apparatus may further comprise a bottom surface spaced apart from the top surface with the compressible inner layer being disposed between the top and bottom surfaces.
Further disclosed herein is a mattress arranged for use with a personal support device, such as a hospital bed, for alleviating the excessive pressure development on plurality of body areas. The apparatus comprises at least one cushion having a bottom surface, a top surface spaced from the bottom surface, the top surface having a plurality of channels formed therethrough. Also disclosed is a compressible inner layer disposed between the top and bottom surfaces, and a plurality of elongate, inflexible members, the members having shaft portions supported by the inner layer and disposed at least partially within the channels. The members further have first ends that extend at least partially through the channels to project beyond the top surface. A cover is Also included for enclosing the at least one cushion, the cover having an upper surface for engaging the first ends, wherein pressure applied to the cover upper surface by contact with the body area causes the members to be displaced axially along the channels toward the bottom surface without deformation. At least some of the plurality of members have longitudinally extending shaft portions and first ends supported by the shaft portions. The first ends have a tapered head configuration to focus the applied pressure upon the body area. The mattress may include a plurality of cushions each selectively comprised to accommodate different portions of a body lying on the bed, wherein the plurality of cushions comprises a head portion, a torso portion, and a feet portion, corresponding to those respective portions of the body. Any of the disclosed apparatus or mattresses may include a thin, impermeable membrane to provide moisture protection to the cushion, which is disposed proximate the lower surface of the cover topper surface, between the topper surface and the first ends of the members. Similarly, a membrane may be disposed between inner layer and shaft portions, to impede perforation of inner layer by members during use.
The above objects and other objects, features, and advantages of the present invention are readily apparent from the following detailed description of the best mode for carrying out the invention when taken in connection with the accompanying drawings wherein like reference numerals correspond to like components.